Abstract: Optical communication systems and methods that provide subliminal in-band signaling of network management information in coherent phase shift keyed (PSK) optical networks. The advantages of this method over various prior art are twofold: (1) It does not require an extra wavelength division multiplexed optical channel to transmit network management data, and (2) it does not require expensive complete time division demultiplexing of the payload data to extract the network management information. The management channel data is transmitted in a spread spectrum signal format that is below the limit of detection in the transmission channel, hence the term subliminal. The subliminal signal is detected using correlative techniques (despreading). The spread-spectrum signal is a direct sequence binary PSK representation of the management channel data plus a spreading code. This spread spectrum signal is superimposed as a slow phase modulation on top of the transmitted high speed PSK payload signal.